An absolute positioning system, for example, a Global Navigation Satellite System (GNSS), may be a sensor of choice for outdoor, land-based navigational tasks. Examples of GNSS include GPS (Global Positioning System), GLONASS (Global Navigation Satellite System), Galileo and Beidou. However, obstructions of the signals between the GNSS transmitters and the receiver may result in the loss of GNSS signals by the receiver. Buildings, trees and other similar obstructions may contribute to the loss of such signals for GNSS receivers operating at, or near, ground level.
In order to compensate for time intervals when a signal from an absolute positioning system may be unavailable, many autonomous navigation systems may use gyroscopes, vision-based navigation, LIDAR, odometry and other navigation techniques in addition to the absolute positioning system to provide additional navigational stability. However, drift in a gyroscope and other sensors may result in unbounded growth of errors in the estimation of heading.
Calibration methods and systems for determining gyroscope drift and other sensor drift may be desirable.